Method of cleaning metal



Aug. 3, 1943.

C. J. KROGEL METHOD OF CLEANING METAL Filed March 5, 1958 INVENTOR c. 4. no em.

RMWJ A iron/v5 r s UUFUi UHLU credits? parts secured to and directly supported thereb such as the tank 3%) and tray 3| particularly, are maintained at an alternating electric potential relativelyl to ground; and are insulated" from ground by'the members 2i. Asir'nble means-to provide and maintain this potential is diagrammatically indicated in the drawing at 6t andis believed to need no particular description-bee yond the diagram, the generator "Gl being-de signed to provide appropriate,ialternating ioure rent, and the transformerb2fbeing adjustably variable.

The tank 30' is filled, preferablyz to about the =r-v level of the bottom of the tray'3'lv as shown, with a. suitable electrolytic cleaning solution-'contain-- ing both .an electrolyteto carry current. between the trayend the strand.passingjbetweef dams-33f and; and a foaming. agent; I;

Preferably the electrolyte iis relativel poisonous "and alkaline, as solutions'ci such ref generally speaking, relatively. less dangeroustand difiicult to handle n ,others metal, silicates; phosphates,. carbonates and hydrox'ides,"sino'e the electrolysis ti'i'sucli solutions produces no poisonous or corrosive gases; 'Qtherbe w e ec r t s m e ewv. precautions are. taken.

Gene rallyQithe; electrolysis wit il alte'rn ting current'j'of.solutions of. thesefe trolytes p1 cuce's an evolution at the-electrodes er? plqdable and, inflammable mixture 'oihyd gen and oxygen. I I If no particular precaiitions taken. this deto nating .gasfi maygbecome s trapped or pocketed indangerous quantities in the a aratus instead-of being nalfgnies'sm eilut'edinto the atmosphere, I

.It has been discovered that the 4 of a suitable foaming. agent to'thesolution e.. .'g. such substancesas ordinary soap rosinfoil soapmr any soluble :soap, saponimsulphonated 0'1; halogeiiated higher alcohols andQthe like; effects ,the

result that the evolved gas-is entrapped in iseg;

regated small portions in theQbubbIes of arnass,

of foam, in such fashion that even the; gas' is accidentally-ignited noisevere explosion can take place and frequently 1 even the V, propagation ct;v the ignition from bubble-toqbubble issmothered.

out and halted. Insome instances; it maybe well to addglycerine to" aid in toughening the,

Inone illustrative example the apparatus; asdisclosed, was arranged to handle fifty several strandsoii-Zt gage (A. WcG.) copper wirerun ning parallel to each otheiyover rollers 50 and 51 and over andin contact with the tops of'the dams 32, 33', 34, 35, ll and 42. The tank .30 was filled, about to the indicated leveL with a solution made up in the following proportions;

lution being suilicient to bank the solutidnnpv above the dams enough to-bury the wires.

The generator 6| was proportioned and the transformer 62 proportioned and adjusted, so. that the current density at the surface of'the.

wires 19 between the dams 33 and' 34 was roughly 1.25 amperes per sq. cm. running be tween lower and upper limits of about 1.0 Land i v Suitable, :Sllbr stances 'for this purpose are such: 'as the} alkali 1.5 amperes per sq. cm. In this particular instance the distance between the dams 33 and 34 was about 9.75 inches, and the wires l9 advan'cedat a rate of about 125113.138! min.

Under these conditions the surface of the wire is satisfactorily cleaned and freed of undesired foreign matter. A toughly tenacious foam forms gradually on the surface of the liquor in the tray.3| and is swept along toward the right by-:the motionofthewires and partly falls over the dam 34 to reston the surface of the solution-in the tank til. Chiefly, however, because of, its lightnessand coherent toughness, it is swept on and falls over the right hand edge of the tank 3H. It is carried down into the bottom of the tank. 30 partlyv by its own. Weight and partly, by the sheet of water overbrimming the dam 4'! towarcithetankffiil, which, carries the foam down to where it is swept out ,via the outlet 23. I Thisfoam not only entraps the gases evolved in, the solution by the electrolytic cleansing action' 'on the wires, .but'also entraps andlcarries away the 'dirt and solid debris cleaned from the wires, so that this last isthusautomatically dis,-

posed of, whereas, in the absence ofa ioaming agent in the solution, such substances remain in and. gradually foul thecleaning bath to unusab-ility. By the present; method,'. however,-the bath remains clean substantially indef nitely,

Theclean wash water overbriimning. the damll "prevents the entry of any of the ioaminto the tank 43 and so helps to maintain this rinsing bath clean. In the bath ill the residueof the cleaningsolutionis washed from thesuri'ace of the wire, and the latter emerges over the rollerf 5| clean and bright. k The distance between thedams. 35 and {it maybe pra-ctically'whatever;

convenience may dictate, providedit be great enough to allow the foam to fall through. -In{the particular instance considered,. this distance was about an inch.

While in the instant case the use generate, ingcurrent is preferred, it is clear that direct articularly.

curre ntmay also be useclif; desired, p

for example in the caseor an article, of mate rial subject, to severe. cathodic but not anodic corrosion or vice versa,

The particular apparatus used te -illustrates.

the practise of the method of the invention forms nqpart of the invention, having been income. mercial use for the practise of other methods for several years. i

I The inventiodclainied resides whollyin method disclosed herein in an illustrativeiex ample, but is not confined to the particular -de-- 1 tails of the illustration, which may be modified and departed from in various ways without de parting from the spiritand scope of the;inven: tion as particularly pointed out in the append-- edclaims.

liVhat is claimed is: i

1. A method of cleaningthe surface of a metallicarticle which comprises steps of immersing.

- the surface to be cleaned. in a bath comprising. a water solution of tin-alkaline electrolyte and: a foaming agent, andpassing an alternating electric current through the bath between the,

article .as one electrode; and another electrode;

the .detonating gas liberated at the electrodescoasting with the foaming agent in-the bath to form a foam on the bath in which both the gas and foreign matter released from the suri'aceby; the electrolytic action are entrapped to be harms, lessly carried away.

2. A method of cleaning the surface of a metallic article which comprises steps of immersing the surface to be cleaned in a bath comprising'a Water solution of an alkaline electrolyte and a foaming agent, passing an alternating electric current through the bath between the article as one electrode and another electrode, the detonating gas liberated at the electrodes coacting with the foaming agent in the bath to form a foam on the bath in which both the gas and foreign matter released from the surface by the electrolytic action are entrapped, and carrying away the foam to remove the entrapped gas and foreign matter.

3. A method of cleaning the surface of a metallic article which comprises steps of immersing the surface to be cleaned in a bath comprising a water solution of an alkaline electrolyte and a foaming agent, passing an alternating electric current through the bath between the article as one electrode and anotherelectrode, the detonating gasliberated at the electrodes co-acting with the foaming agent in the bath to form a foam on the bath in which both the gas and foreign matter released from the surface by the electrolytic action are entrapped, and creating relative motion of the article and bath to carry away the foam and the entrapped gas and foreign matter.

4. A method of cleaning the surface of a metallic article which comprises steps of immersing the surface to be cleaned in a bath comprising a water solution of an alkaline electrolyte and a foaming agent, passing an alternating electric current through the bath between the article as one electrode and another electrode, the detonating gas liberated at the electrodes coacting with the foaming agent in the bath to form a foam on the bath in which both the gas and foreign matter released from-the surface by the electro- I lytic action are entrapped, and circulating the vbath to'create a current therein to carry away 1 the foam and the entrapped gas and foreign matter,

one electrode and another electrode,'the detonating gas liberated at the electrodes coacting' with I the foaming agent in the bath toform a foam on the bath in which both the gas and foreign i matter released from the surface by the electrolytic action are entrapped, and moving the article throughthe bath to sweep the foam and the entrapped gas and foreign matter therefrom.

6. A'method of cleaning the surface of a me- 7 tallic article which comprises steps of immersing the surface to be cleaned in a bath comprising a water solution of an alkaline electrolyte and a foaming agent, passing an alternating electric current through the bath between the article as one electrode and another electrode, the detonat- -.lng gas liberated at the electrodes coacting with the foamingagent in the bath to form a foam on Q the bath-in which both the gas and foreign matthe surface to be cleaned in a bath comprising a water solution of an alkaline electrolyte and a foaming agent, passing an alternating electric current through the bath between the article as one electrode and another electrode, the detonating gas liberated at the electrodes coacting with the foaming agent in the bath to form a foam on the bath in which both the gas and foreign matter released from the surface by the electrolytic action are entrapped, and removing the foam with its entrapped gas and foreign matter from the article.

8. A method of cleaning the surface of a metallic article which comprises steps of immersing the surface to be cleaned in a bath comprising a water solution of an alkaline electrolyte and a sufficient quantity of a foaming agent to produce in coaction with gas evolved into the bath a layer of foam on the surface of the bath, and passing an alternating electric current through the bath between the article as one electrode and another electrode, the detonating gas liberated at the electrodes coasting with the foaming agent in the bath to form a foam on the bath in which both the gas and foreign matter released from the surface by the electrolytic action are entrapped to be harmlessly carried away.

9. A method of cleaning the of metallic articie which comprises steps or immersing the surface to be cleaned in a bath comprising a water solution of an alkaline electrolyte and a sufficient quantity of a soluble soap to produce in coaction with gas evolved into the bath a layer of foam on the surface of the bath, and passing an alternating electric current through the bath between the article as one electrode andanother electrode, the detonating gas liberated at the electrodes coacting with the foaming agent in the bath to form a foam on the bath in which both the gas and foreign matter released from the surface by the electrolytic action are entrapped to be harmlessly carried away.

10. A method of cleaning the surface of a me: tallic article which comprises steps of immersing the surface to be cleaned in a bath comprising a water solution of an alkaline electrolyte and a action with gas evolved into the bath a layer of foam on the surface of the bath, and passing an alternating electric current through the bath be tween the article as one electrode and another electrode, the detonating gas liberated at the electrodes coacting with the foaming agent in the bath to form a foam on the bath in which both the gas and foreign matter released from the surface by the electrolytic action are entrapped to be harmlessly carried away.

11. A method of cleaning the surface of a metallic article which comprises steps of immersing the surface to be cleaned in a bath comprising a water solution of an alkaline electrolyte and a suflicient quantity of a sulphonated alcohol to ter released from the surface by the electrolytic 1 action areentrapped, circulating the bath to create a current therein to carry away the-foam and the entrapped'gas and foreign matter and moving the article through the bath to sweep the i foam and the-entrapped gas and foreign matter therefrom. j

,7- .5. {9 333 9?. fietmli ilifi FR EQPi. a i

produce in coaction with gas evolved into the bath a layer of foam on the surface of the bath, and passing an alternating electric current through the bath between the article as one electrode and another electrode, the detonating gas liberated at the electrodes coacting with the foaming agent in the bath to form a foam on the bath in which both the gas and foreign matter, -re1easecl from the surface by the electrolytic action are entrapped to be harmlessly carried away.

CHRISTOPHER J. KROGEL 

